Biology subjects

Gatto, F.

Publications and source records attributed to Gatto, F..

3 recordsLinked to original sources

bioRxiv2021

Analysis of Normal Levels of Urine and Plasma Free Glycosaminoglycans in Adults

Plasma and urine glycosaminoglycans (GAGs) are long linear sulfated polysaccharides recognized as potential non-invasive biomarkers for several diseases. However, owing to the analytical complexity associated with the measurement of GAG concentration and disaccharide composition, the so-called GAGome, a reference study of the normal healthy GAGome is currently missing. Here, we prospectively enrolled 308 healthy adults and analyzed their urine and plasma free GAGomes using a standardized ultra-high-performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry (UHPLC-MS/MS) method together with comprehensive demographic and blood chemistry biomarker data. Of 25 blood chemistry biomarkers, we mainly observed weak correlations between the free GAGome and creatinine in urine, and hemoglobin or erythrocyte counts in plasma. We found higher free GAGome concentration - but not composition - in males. Partitioned by gender, we established reference intervals for all detectable free GAGome features in urine and plasma. We carried out a transference analysis in healthy individuals from two distinct geographical sites, including the Lifelines Cohort Study, which validated the reference intervals in urine. Our study is the first large-scale determination of normal plasma and urine free GAGomes reference intervals and represents a critical resource for physiology and biomarker research.

biochemistry↗

bioRxiv2021

Analytical Performance of a Standardized Kit for Mass Spectrometry-based Measurements of Human Glycosaminoglycans

Glycosaminoglycans (GAGs) are long linear sulfated polysaccharides implicated in processes linked to disease development such as mucopolysaccharidosis, respiratory failure, cancer, and viral infections, thereby serving as potential biomarkers. A successful clinical translation of GAGs as biomarkers depends on the availability of standardized GAG measurements. However, owing to the analytical complexity associated with the quantification of GAG concentration and structural composition, a standardized method to simultaneously measure multiple GAGs is missing. In this study, we sought to characterize the analytical performance of a ultra-high-performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry (UHPLC-MS/MS)-based kit for the quantification of 17 GAG disaccharides. The kit showed acceptable linearity, selectivity and specificity, accuracy and precision, and analyte stability in the absolute quantification of 15 GAG disaccharides. In native human samples, here using urine as a reference matrix, the analytical performance of the kit was acceptable for the quantification of CS disaccharides. Intra- and inter-laboratory tests performed in an external laboratory demonstrated robust reproducibility of GAG measurements showing that the kit was acceptably standardized. In conclusion, these results indicated that the UHPLC-MS/MS kit was standardized for the simultaneous measurement of GAG disaccharides allowing for comparability of measurements and enabling translational research. SummaryAnalytical performance of a kit for standardized GAG measurements, based on an established UHPLC-MS/MS method

biochemistry↗

bioRxiv2020

Purine metabolism regulates DNA repair and therapy resistance in glioblastoma

Intratumoral genomic heterogeneity in glioblastoma (GBM) is a barrier to overcoming therapy resistance, and new strategies that are effective independent of genotype are urgently needed. By correlating intracellular metabolite levels with radiation resistance across dozens of genomically-distinct models of GBM, we found that purine metabolites strongly correlated with radiation resistance. Inhibiting purine, but not pyrimidine, synthesis radiosensitized GBM cells and patient-derived neurospheres by impairing DNA repair in a nucleoside-dependent fashion. Likewise, administration of exogenous purine nucleosides protected sensitive GBM models from radiation by promoting DNA repair. Combining an FDA-approved inhibitor of de novo purine synthesis with radiation arrested growth in GBM xenograft models and depleted intratumoral guanylates. High expression of the rate-limiting enzyme of de novo GTP synthesis was associated with shorter survival in GBM patients. Together, these findings indicate that inhibiting de novo purine synthesis may be a promising strategy to overcome therapy resistance in this genomically heterogeneous disease.

neuroscience↗